OK this is a 2 part question, I've seen and searched for several methods to get a list of unique values for a class and haven't been practically happy with any method so far.
So anyone have a simple example code of getting unique values for instance for this code. Here is my super slow example.

class LinkRating2(db.Model):
    user = db.StringProperty()
    link = db.StringProperty()
    rating2 = db.FloatProperty()

def uniqueLinkGet(tabl):
    start = time.time()
    dic = {}
    query = tabl.all()
    for obj in query:
        dic[obj.link]=1
    end = time.time()
    print end-start
    return dic

My second question is calling for instance an iterator instead of fetch slower? Is there a faster method to do this code below? Especially if the number of elements called be larger than 1000?

query = LinkRating2.all()
link1 = 'some random string'
a = query.filter('link = ', link1)
adic ={}
for itema in a:
    adic[itema.user]=itema.rating2